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Fixed in 2021.2.X

Fixed in 2020.3.X, 2021.1.X



Found in





Issue ID




[iOS] Player crashing when connecting external Display via USB-C port

Mobile Graphics


Reproduction steps:
1. Open the project in ""
2. Build for iOS
3. Connect an external display to the device using a USB-C port
4. Wait for the view to show up in the external monitor
5. Move around in the game using to fingers

Expected result: Nothing significant related to memory happens
Actual result: Memory will increase very fast and the application will crash

Reproducible with: 10.5.0 (2020.3.9f1) 11.0.0 (2021.1.8f1) 12.0.0 (2021.2.0a18)
Not reproducible with: 4.10.0 (2018.4.35f1), 7.6.0 (2019.4.27f1)

Devices reproducible with:
iPad Air4 (iOS 14.0)
Devices not reproducible with:
iPad Pro 12.9 1st gen (iOS 13.4.1)

1. The project uses URP, I am not sure if it is related to the memory problem
2. The issue only occurs when using USB-C connection
3. The customer provided testing results using different devices (clearly visible that issue is present with USB-C port only)

  1. Resolution Note (fix version 2021.2):

    Fixed in 2022.1.0a4

  2. Resolution Note (fix version 2021.2):

    Fixed in 2021.2.0b6

  3. Resolution Note (fix version 2021.1):

    Fixed in 2021.1.18f1

  4. Resolution Note (fix version 2020.3):

    Fixed in 2020.3.17f1

Comments (5)

  1. Guache_art

    Aug 17, 2021 15:51

    Any updates?
    Please help us!

  2. Andy-StudioBuzzword

    Jul 09, 2021 13:06

    After seeing this issue with our project I have managed to make a build in 2021.1.13f1 which successfully connects to an external monitor without the Metal allocation causing the app to crash.

    The changes I made to the projects settings were:

    - Set Active Input Handling to: Input System Package (new) and ensure all Event System objects are using the new module
    - Check 'Metal Write-Only Backbuffer'
    - Set Memoryless Depth to 'Automatic'

    I also ensured that no cameras were assigned to Display 2 in the editor and assigned them with code after a short pause.

    The build has been running on 5 iPads for 8 hours at a time with no issues so I'm confident this does resolve the problem.

  3. makimono79

    Jul 02, 2021 08:47

    Any updates on this issue? It is very urgent for our user community. Please help!

  4. DasGnu

    Jun 04, 2021 11:30

    Yes please, help Unity!

    Our Tagtools desperately needs to be hooked on an external display.

    Mille Gracie,

    Josef Dorninger

  5. gokhanokur

    Jun 04, 2021 10:46

    Please help us with this problem.
    Thank you

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